A robot section, such as a part of a robot arm is often controlled by a motor, such as a servo motor, together with a gear box.
The control of industrial robots may in theory be so precise that the deviation from a desired position is very small. This allows the robot to perform fine and precise operations.
However, it has been found that the robot movement deviation varies because of the gear box temperature. This means that the movements are not as precise anymore. If a robot is to be used in production, this may lead to unacceptable low quality of the products produced.
Various documents discuss handling of temperature drift in a motor, see for instance U.S. Pat. No. 5,420,490, or in a robot in general, see EP 2199036.
There is in view of this still a need for providing a compensation of the drift caused by temperature variations in a gear box.